In a variety of electronic systems, it is useful to modulate a beam of charged particles, such as electrons or ions. Electron beams are employed in heating systems, imaging systems, display systems, and high-frequency (e.g., radio frequency) signal processing. Examples of systems employing ion beams include neutron generators, which may be used to detect nuclear materials, explosives, landmines, drugs, or other contraband, and which may have industrial applications, such as qualifying coal streams, cement, or other commodity items. In these systems, as well as others, the flow of charged particles may be modulated, e.g., turned on, turned off, increased, decreased, or cycled at some frequency.
In particular, it may be useful to modulate the beam of charged particles with an electromagnetic radiation source, e.g. a light source, such as a laser. Electromagnetic radiation may convey signals with a relatively high frequency, and in some instances, these signals may be transmitted between electrically isolated components.